Tuesday, July 30, 2013

July Ends Dry; However, August Doesn't Start Dry

We have today and probably tomorrow to appreciate some dry weather in the region as high pressure holds serve and keeps our humidity levels modest and temperatures that are pretty close to the seasonal averages for late July.

We close July dry but we don't start August that way -- a storm system will approach the region on Thursday and bring us showers and storms as a ripple of low pressure pushes towards the region from the southwest and crosses the region during the course of the day.

Modeling shows an increase in atmospheric moisture ahead of the frontal boundary. PWAT's (measure of moisture in a single column of the atmosphere) approach two inches again, which shows the potential for heavy rain with any thunderstorm that develops. To put it in perspective, PWAT's on Sunday afternoon were around 1.7" in the city and South Jersey, with PWAT's on Monday around 0.5" (I'm sure you noticed how blue the skies were and how dry the atmosphere was...kinda had an early September feel to the air). With added moisture and humidity working back into the region, the potential for heavy rain does exist with any thunderstorms that fire...and modeling shows Thursday into Thursday evening the prime time for thunderstorm development in the region.

Some spots will pick up an inch of rain, perhaps two inches of rain, on Thursday. Odds favor the greatest chances of this to be northwest of the city as of now but that may change as we approach Thursday's event. Some localized flooding can't be ruled out in parts of the region, especially in those areas that pick up the highest rainfall totals.